U.S. patent application number 15/578568 was filed with the patent office on 2018-06-21 for method and apparatus for zigzag folding a material web.
The applicant listed for this patent is TECHNISCHE UNIVERSITAT BERLIN. Invention is credited to Muhammed AYDEMIR, Gordon BACH, Arne GLODDE, Robert MOOY.
Application Number | 20180170705 15/578568 |
Document ID | / |
Family ID | 56134046 |
Filed Date | 2018-06-21 |
United States Patent
Application |
20180170705 |
Kind Code |
A1 |
GLODDE; Arne ; et
al. |
June 21, 2018 |
METHOD AND APPARATUS FOR ZIGZAG FOLDING A MATERIAL WEB
Abstract
The application relates to a method for zigzag folding a
material web, the method having the following steps: continuously
feeding a material web to be folded into a folding apparatus along
a feed direction, alternately gripping the material web in a
proximal region of the folding apparatus by means of gripping
devices, holding and conveying the material web by means of the
gripping devices into a distal region of the folding apparatus, the
material web being zigzag folded thereby, and releasing the
material web from the gripping devices and depositing the material
web in a stack (9) with folds in the distal region, a distance
between adjacent gripping devices (4, 5) being equal to a fold
length. Furthermore, the application also relates to an apparatus
for zigzag folding a material web.
Inventors: |
GLODDE; Arne; (Berlin,
DE) ; BACH; Gordon; (Berlin, DE) ; MOOY;
Robert; (Wunstorf, DE) ; AYDEMIR; Muhammed;
(Berlin, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TECHNISCHE UNIVERSITAT BERLIN |
Berlin |
|
DE |
|
|
Family ID: |
56134046 |
Appl. No.: |
15/578568 |
Filed: |
June 1, 2016 |
PCT Filed: |
June 1, 2016 |
PCT NO: |
PCT/DE2016/100253 |
371 Date: |
November 30, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65H 2405/552 20130101;
B65H 45/1015 20130101; H01M 10/0583 20130101; Y02E 60/10 20130101;
B65H 2301/44331 20130101; H01M 10/0459 20130101; H01M 10/0404
20130101; B65H 45/101 20130101; B65H 2301/44338 20130101; H01M
10/0525 20130101; B65H 2301/44331 20130101; B65H 2701/13212
20130101 |
International
Class: |
B65H 45/101 20060101
B65H045/101; H01M 10/04 20060101 H01M010/04; H01M 10/0525 20060101
H01M010/0525; H01M 10/0583 20060101 H01M010/0583 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 1, 2015 |
DE |
10 2015 108 651.4 |
Claims
1. A method for zigzag folding a strip material, wherein the method
has the following steps: continuously supplying a strip material to
be folded to a folding apparatus along a supply direction,
alternate gripping of the strip material in a proximal region of
the folding apparatus by means of gripping devices, which gripping
devices are guided from opposite sides of the strip material, and
spaced apart, to the proximal region, holding and transporting the
strip material by means of the gripping devices into a distal
region of the folding apparatus, wherein the strip material is
zigzag folded at the same time, and releasing of the strip material
by the gripping devices and placement of the strip material in a
stack with folds in the distal region, wherein the folds extend in
the stack transversely to the supply direction, wherein, for each
of the gripping devices, one straight connecting line runs
diagonally to the supply direction on the opposite sides of the
strip material, between a proximal position of the gripping device
during gripping of the strip material in the proximal region and a
distal position of the same gripping device during the release of
the strip material in the distal region, and wherein a spacing
between adjacent gripping devices is equal to a fold length.
2. The method according to claim 1, wherein the gripping devices
are guided on the opposite sides of the strip material, between the
proximal position and the distal position, at least in sections,
along a movement path which runs along the straight connecting
line.
3. The method according to claim 1, wherein the gripping devices
are guided on the opposite sides of the strip material by means of
a respective transport device on a closed movement path from the
proximal region, via the distal region, back again to the proximal
region.
4. The method according to claim 1, wherein the gripping devices
grip the strip material at the edge on opposite sides of the strip
material.
5. The method according to claim 1, wherein the supply direction is
orientated horizontally.
6. The method according to claim 1, wherein inserts are arranged in
at least a portion of the folds of the stack.
7. The method according to claim 6, wherein the inserts are guided
to the strip material before and/or during the zigzag folding.
8. The method according to claim 6, wherein the inserts are
arranged such that they adhere to the strip material, before the
strip material is placed in the stack.
9. The method according to claim 6, wherein the strip material is a
separator material made from an electrically insulating material
and the inserts are electrodes, so that the stack is produced as a
zigzag-folded stack with anodes, cathodes and separator.
10. An apparatus for zigzag folding a strip material, having a
supply device, configured to continuously supply a strip material
to be folded to a folding apparatus along a supply direction, and
gripping devices, configured to grip the strip material in a
proximal region of the folding apparatus, wherein the gripping
devices are guided by means of a transport device from opposite
sides of the strip material, and spaced apart, to the proximal
region, to hold the strip material and to transport the same into a
distal region of the folding apparatus, wherein the strip material
is zigzag folded at the same time, and to release from the strip
material and to place the strip material in a stack with folds in
the distal region, wherein the folds extend in the stack
transversely to the supply direction, wherein, for each of the
gripping devices, one straight connecting line runs diagonally to
the supply direction on the opposite sides of the strip material,
between a proximal position of the gripping device during gripping
of the strip material in the proximal region and a distal position
of the same gripping device during the release of the strip
material in the distal region, and wherein a spacing between
adjacent gripping devices is equal to a fold length.
Description
[0001] The invention relates to a method and an apparatus for
zigzag folding a strip material.
BACKGROUND
[0002] Methods of this type for zigzag folding a strip material can
be used in various applications, inserts can be arranged in the
folds of the folded strip material, whether it be in all folds or
only in a portion of the folds. A method for zigzag folding can for
example be used in connection with the production of a cell
composite of battery cells.
[0003] Cell production of this type knows multiple different cell
cores, for example for the construction of lithium-ion battery
cells. However, these generally differ in terms of the composition
of their individual components, an electrode separator composite
(cell composite), not from one another. The composite structure of
the cell core constitutes the structural design by means of the
different production methods. In the general prior art, a
distinction is made between four composite structures: The
round-wound and the prismatically-wound composite structure, the
stacked structure and the zigzag-folded composite structure.
[0004] The round-wound composite structure generally consists of a
cathode and anode web, which is wound together with two separators.
The flat-wound composite structure differs from the round-wound
composite structure by a flat winding core with ellipsoidal
shape.
[0005] The folded composite structure is based on the use of a
regularly zigzag-folded continuous separator strip, into which
preassembled electrode sheets are alternately introduced. It is
known from DE 10 2010 055 611 A1 to only provide anodes and
cathodes as pre-cut sheets, and instead to provide the separator
and pre-fold the same to the dimensions of the finished stack. US
2014/0101928 A1 describes an opposing shift register for creating a
zigzag fold with simultaneous introduction of many electrode sheets
during folding. A method for producing an electrode stack made up
of cathode, anode and separator for a battery is described in DE 10
2010 055 617 A1. At least one of these components, generally the
separator, is present as a continuous material. The separator
material is supplied unfolded and equipped with at least one
tailored component. Subsequently, this composite is folded with
electrodes already placed and fixed. This method therefore differs
from DE 10 2010 055 611.4 in that the separator is not already
provided as a pre-folded continuous material. This therefore
overcomes the problems of the dimensional accuracy of the separator
owing to extensions/shrinkages in the pre-folded state.
[0006] DE 10 2010 055 608 A1 describes a method for producing an
electrode stack, in which a layer of the electrode stack is present
as a continuous material and is folded alternately. The two other
layers are inserted into the pockets produced by the folding. The
folding is created by means of arrangement of boundary rods,
between which the material is introduced. The rods are subsequently
pulled out laterally. The design of the zigzag-folded cell core is
characterized by a continuous separator with either electrodes
which are already place, or with electrodes subsequently inserted
into the folds.
[0007] The design of stacked cell composites essentially differ,
due to the sheet-like design of the separator material, from those
of the wound and folded composite structures, in which the
separator is generally present in a strip-shaped manner. A method
for stacking individual layers for producing a battery cell is
described in U.S. Pat. No. 4,080,728 A. Here, all constituents of
the cell core are joined as cut individual elements to form a
stack.
[0008] Like the stacking method, the folding method also counts
among the oldest of composite production. In 1984 already, a method
for continuous composite production was presented in U.S. Pat. No.
4,479,300 A. Here, electrode sheets are inserted alternately into
the folds of an already continuously folded separator strip. Due to
the high process throughputs and the high composite quality of
winding methods, predominantly round cells were produced in the
commercialization of lithium-ion battery cells in the year 1990.
However, since 2000, the demand for compact, flat lithium-ion
battery cells increased again due to the miniaturization of
electronic devices. As a result, the focus of industrialized
production technology returned to the automation of the folding or
stacking composite production.
[0009] But also in connection with other applications, there is a
need for improved technologies for folding.
[0010] A method and an apparatus for placing a flexible strip
material are specified in the document DE 10 2012 022 751 B4,
wherein the strip material is supplied by means of a supply device
and placed in a zigzag-shaped manner on a placement position by
means of a laying device, wherein the strip material is contacted
by at least two engagement elements of the laying device, which can
be moved in at least two opposing laying directions, after exiting
the supply device, and is guided to the placement position. The
engagement elements change their position during the contact with
the strip material between an engagement position and a release
position. During the transport, the strip material rolls on a
contact section of the engagement element.
[0011] An apparatus for folding and stacking printed paper is
described in the document DE 26 34 300 A1. Measures are provided
for constantly pressing down the placed paper in the region of the
folded edges.
SUMMARY
[0012] It is the object of the invention to specify a method and an
apparatus for zigzag folding a strip material, enabling continuous
folding with the highest possible throughput.
[0013] To achieve this, a method and an apparatus for zigzag
folding a strip material with inserts arranged in folds according
to independent Claims 1 and 10 are provided. Embodiments are the
subject-matter of dependent sub-claims.
[0014] According to one aspect, a method is created for zigzag
folding a strip material, in which a strip material to be folded is
supplied continuously to a folding apparatus along a supply
direction. The strip material is gripped alternately in a proximal
region of the folding apparatus by means of gripping devices,
wherein the gripping devices are guided from opposite sides of the
strip material and spaced apart to the proximal region. The strip
material is held by means of the gripping devices and transported
into a distal region of the folding apparatus, wherein the strip
material is zigzag folded at the same time. In the distal region,
the strip material is released by the gripping devices and placed
in a stack with folds, wherein the folds extend in the stack
transversely to the supply direction. For each of the gripping
devices, one straight connecting line runs diagonally to the supply
direction on the opposite sides of the strip material, between a
proximal position of the gripping device during gripping of the
strip material in the proximal region and a distal position of the
same gripping device during the release of the strip material in
the distal region. A spacing between adjacent gripping devices,
which successively grip the strip material to be folded during the
gripping of the same, corresponds to a folding length, that is to
say the spacing between successive folds along the zigzag-folded
strip material.
[0015] According to a further aspect, an apparatus is provided for
zigzag folding a strip material. The apparatus has a supply device,
which is configured to supply a strip material to be folded to a
folding apparatus along a supply direction. Gripping devices are
provided, which are configured to grip the strip material in a
proximal region of the folding apparatus, to hold the strip
material and transport the same into a distal region of the folding
apparatus, wherein the strip material is zigzag folded at the same
time, and to release from the strip material and place the strip
material in a stack with folds in the distal region. The gripping
devices are guided by means of a transport device from opposite
sides of the strip material, and spaced apart, to the proximal
region. Folds extend transversely to the supply direction in the
stack of the placed strip material. For each of the gripping
devices, one straight connecting line runs diagonally to the supply
direction on the opposite sides of the strip material, between a
proximal position of the gripping device during gripping of the
strip material in the proximal region and a distal position of the
same gripping device during the release of the strip material in
the distal region. A spacing between adjacent gripping devices,
which successively grip the strip material to be folded during the
gripping of the same, corresponds to a folding length, that is to
say the spacing between successive folds along the zigzag-folded
strip material.
[0016] The gripping and the holding of the strip material may be
realized by means of gripper elements of the gripping device.
[0017] The gripping devices grip the strip material to be gripped
successively at a spacing, which corresponds to the fold length, so
that the spacing between adjacent gripping positions (adjacent
gripping device) along the strip material, which extends in a
straight line, that is to say positions, in which the strip
material is gripped by a respective gripping device, is equal to
the fold length.
[0018] Here, it is not necessary that the strip material to be
folded extends in the stretched position (along a straight line),
during gripping nor during transport into the placed position after
gripping. The course of the strip material may deviate from such a
straight position, for example sag. In any case, the dimension of
the spacing of adjacent gripping devices corresponds to the fold
length when the strip material extends along a (possibly imaginary)
straight line.
[0019] A spacing between successive gripping devices during the
movement thereof along a movement path may be set before operation,
for example by using adjustable gripping devices, in which the
relative position with respect to the adjacent gripping devices may
be changed. The set spacing is then fixed for operation, namely to
the fold length.
[0020] The straight connecting lines on the two sides of the strip
material may be arranged in accordance with a V position. An angle
between the supply direction and the respective straight connecting
line may be an acute angle. The angle between the two straight
connecting lines may be acute.
[0021] A supply speed for supplying the strip material to be
folded, which may be realized in a clocked manner, and also a
transport speed for transporting the gripping devices to the
proximal region may be adjustable independently of one another. The
supply speed and the transport speed may be adapted to one
another.
[0022] The strip material to be folded is gripped by means of the
gripping devices and held during the displacement of the gripping
devices to the proximal region. For example, during gripping, the
strip material is clamped between gripping arms or held by means of
a friction fit. Thus, no relative movement takes place between a
gripped strip material section and the gripping device during
transport, particularly in relation to their active gripping or
gripper elements.
[0023] The gripping devices may each be guided on the opposite
sides of the strip material, between the proximal position and the
distal position, at least in sections, along a movement path which
runs along the straight connecting line. This may mean that the
transport device, using which the gripping devices are each
transported and guided on the opposite sides of the strip material
between the proximal and the distal position, has a straight course
(movement path) entirely or in part between the two positions.
[0024] The gripping devices may be guided on the opposite sides of
the strip material by means of a respective transport device on a
closed movement path from the proximal region, via the distal
region, back again to the proximal region. The closed movement path
of the respective transport device may have curved and straight
movement paths. For example, an oval movement path may be provided,
in which at least on one longitudinal side, a straight course is
formed, particularly on a side opposite the strip material.
Alternatively, the gripping devices may be moved back and forth
between the proximal region and the distal region along a movement
path, for example between end or holding points of a guide rail
system, which in the sense applied here also corresponds to a
closed movement path.
[0025] The gripping devices may grip the strip material at the edge
on opposite sides of the strip material. The formation of the
gripping connection between the gripping devices and the strip
material may be limited to such an edge grip. Alternatively, edge
gripping may only be provided on one side of the strip
material.
[0026] The supply direction may be orientated horizontally.
Alternatively, the supply direction may be orientated vertically or
in an inclined position. In the embodiments, the folds each run
transversely to the supply direction in the stack of the placed
strip material.
[0027] Inserts may be arranged in at least a portion of the folds
of the stack.
[0028] The inserts ultimately arranged in the folds of the placed
strip material may be guided to the strip material before and/or
after the gripping of the strip material by the gripping devices.
The introduction of the inserts may take place before the zigzag
folding, which begins with the gripping of the strip material by
the gripping devices, is completed with the placement of the strip
material. In the various embodiments, inserts may be supplied on
one or both sides of the strip material. When guiding the inserts
onto the strip material, which is to be folded or is already
partially folded, the supply direction for the inserts may form an
acute angle with the supply direction of the strip material. In the
various embodiments, the inserts may be supplied with the aid of a
transport system transporting the inserts, for example by means of
transport systems which have transport directions, if inserts are
to be supplied on both sides of the strip material.
[0029] The inserts may be guided to the strip material before
and/or during the zigzag folding.
[0030] The inserts may be arranged such that they adhere to the
strip material, before the strip material is placed in the stack.
After supplying the inserts to the strip material to be folded, the
inserts adhere on the surface of the strip material, wherein a
suitable adhesive agent may be provided on the inserts and/or on
the surface of the strip material. It is possible to dispense with
providing an adhesion of the inserts on the strip material if the
inserts guided onto the strip material remain on the strip
material, for example due to gravity, whilst the strip material is
folded. Also, the configuration with regard to the operating
parameters of the folding device may be chosen in a suitable
manner, in order to minimize or completely exclude the necessity
for adhesion of the inserts on the strip material. In this context,
the transport speed of the gripping devices and the oblique
position of the straight connecting lines for the gripping devices
with respect to the supply direction in particular are
important.
[0031] The strip material may be a separating or separator material
made from an electrically insulating material and the inserts may
be electrodes, so that the stack is produced as a zigzag-folded
stack with anodes, cathodes and separator. For example, lithium-ion
battery cells may be produced in this manner. Not only when
producing a zigzag-folded stack with anodes, cathodes and
separator, but also when folding other strip materials, high
folding speeds may be achieved using the suggested technologies.
For example, the method may provide creating at least five folds
per second or alternatively at least ten folds per second.
[0032] In connection with the apparatus for zigzag folding a strip
material with inserts arranged in folds, the embodiments explained
previously in connection with the method may accordingly be
provided.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0033] Further exemplary embodiments are explained in more detail
in the following with reference to figures of a drawing. In the
figures:
[0034] FIG. 1 shows a schematic illustration with a folding
apparatus for the zigzag folding of a strip material with inserts
arranged in folds, before the start of a folding process,
[0035] FIG. 2 shows a schematic illustration with the folding
apparatus from FIG. 1 after the start of the folding process,
[0036] FIG. 3 shows a schematic illustration with the folding
apparatus from FIG. 1 during the folding process, wherein an insert
is arranged on the strip material to be folded,
[0037] FIG. 4 shows a schematic illustration with the folding
apparatus from FIG. 1 in an advanced state of the folding process,
wherein a plurality of inserts are arranged on the strip material
to be folded,
[0038] FIG. 5 shows a schematic illustration with the folding
apparatus from FIG. 1, wherein the strip material to be folded is
partly placed in a stack, and
[0039] FIG. 6 shows a schematic illustration of a gripping
device.
[0040] FIGS. 1 to 5 show schematic illustrations with a folding
apparatus 1 for the zigzag folding of a strip material 2. According
to FIG. 1, the strip material 2 is supplied along a supply
direction of the folding apparatus 1, wherein the supply direction
is orientated vertically and parallel to the strip material in the
exemplary embodiments illustrated. In a proximal region 3 of the
folding apparatus 1, the strip material 2 to be folded is gripped,
in order to then be folded.
[0041] For gripping and transporting the strip material 2 in the
folding apparatus 1, on each of opposite sides of the strip
material 2, a plurality of gripping devices 4, 5 are accommodated
on an assigned transport system 6, 7 in such a manner that the
plurality of gripping devices 4, 5 are each transported to the
proximal region 3 in a circumferential manner and continuously on a
closed movement path. The plurality of gripping devices 4, 5 are
guided in the proximal region 3, spaced apart, to the strip
material 2, in order to grip and to hold the strip material.
[0042] The movement path of the plurality of gripping devices 4, 5
is illustrated schematically in FIGS. 1 to 5. In an implementation,
the movement path will rather run on a curved movement path in the
region of the end faces of the transport devices 6, 7 which are to
be differentiated from the longitudinal sides.
[0043] FIGS. 2 to 5 show the progress of the zigzag folding of the
strip material 2 by means of the folding apparatus 1. Here, the
plurality of gripping devices 4, 5 each move out of the proximal
region 3 of the folding apparatus 1 into a distal region 8 of the
folding apparatus 1, in order then ultimately to place the folded
material in a stack 9 (cf. FIG. 5), in which the folds created run
transversely to the supply direction of the strip material 2. A
straight connecting line A between a position of the gripping
device in the proximal region 2 and a position of the same gripping
device in the distal region 8 of the folding apparatus 1 runs
obliquely to the supply direction of the strip material 2, which is
shown in FIGS. 1 to 5 by means of an angle .alpha..
[0044] According to the illustration in FIG. 2, gripping devices
G.sub.x3 and G.sub.y2 gripping adjacently or successively have a
spacing along the separator web extending in a straight line
therebetween, which spacing corresponds to the fold length.
[0045] In addition to the strip material 2, according to FIGS. 1 to
5, inserts 10 are supplied along a supply direction, which may run
parallel to the longitudinal extent of the inserts and which, in
the example shown, encloses an acute angle with the supply
direction of the strip material 2. After the completion of the
folding process, the inserts 10 are arranged in the stack 9 between
the folds of the strip material 2. In order to localize the inserts
10 on the strip material 2 during zigzag folding, it may be
provided that the inserts 10 adhere on the surface of the strip
material 2, for example in that an adhesive agent, for example a
glue, is arranged on the inserts 10 and/or on the surface of the
strip material 2.
[0046] The described method may be used in order to produce battery
cells from a folded separator material and cathodes and anodes
arranged therebetween in an alternating manner.
[0047] The strip material 2 is then realized as a strip-shaped
separator material. The inserts 10 are cathodes and anodes, which
are supplied from the opposite sides of the strip material 2 to the
strip material 2 and which have a flat shape for example. For
example, a respective transport system may be used for this, for
example on the basis of transport systems with counter-rotating
rollers.
[0048] The described folding process is realized as a continuous
process and for example makes it possible to create at least five
folds per second in the stack 9. Also, a higher folding speed may
be provided, for example the production of at least ten folds per
second.
[0049] FIG. 6 shows a schematic illustration of a gripping device
20, which may be used for the plurality of gripping devices 4, 5. A
storage system 21 with a plurality of rollers is provided, for
example even six or twelve rollers, in order to accommodate the
gripping device 20 on a transport system (not illustrated), which
is set up to transport the gripping device 20 on a circumferential
movement path. Actuatable lever arms 22, 23 are accommodated in a
pivotable manner, in order to support the opening and the closing
of a gripper 24 in which gripping arms 25, 26 are actuated for
example by means of a force mechanism. Alternatively, it may be
provided to actuate the gripper 24 by means of a motor or using a
pneumatic cylinder. The gripping arms 25, 26 are set up to grip the
strip material 2 to be folded at least at the edge.
[0050] The separator material to be folded may be pulled into the
folding device 1 under tensile load as a strip-shaped continuous
material with the speed {right arrow over (V)}.sub.F. The folding
device 1 has the at least two mutually opposite gripper systems, on
the mirror axis of which the strip material 2 is guided. Each
gripper system has n individual gripping devices 4, 5, which may be
moved independently of one another. The guide path of the gripping
devices 4, 5 is circumferential. The gripper systems are in each
case inclined at the opening angle .alpha. to the supply direction.
To create the folds, the grippers of the two gripper systems
synchronize their speed to that of the strip material and fix the
same in an alternating manner.
[0051] At the time of the engagement of the grippers with the strip
material, there is no relative movement between the individual
gripper and the film web ({right arrow over (V)}.sub.F={right arrow
over (V)}.sub.G(x,y)). Previously tailored anode material on one
side and previously tailored cathode material on the other side are
alternately supplied to the method as inserts 10. The electrodes
may be placed on an as yet unfolded separator web and fixed on the
separator web, for example by means of lamination or adhesive
bonding. The separator web is subsequently folded. The anodes and
cathodes, which were previously cut and placed onto the separator
web, lie alternately in the folds as inserts 10.
[0052] The anode supplied to the method may be supplied
simultaneously to pulling the fold along the guide path of the
gripper system of the folding apparatus 1. The cathode may
accordingly be supplied to the folding apparatus along the guide
path of the gripper system.
[0053] The grippers, which are in contact with the strip material,
continuously slow down their speed from the time of the fixing and
thus brake the resulting zigzag-folded film structure with the fold
length and reach the speed 0 ({right arrow over (V)}.sub.Gx3={right
arrow over (V)}.sub.Gy2{right arrow over (V)}.sub.F,B=0) in the
distal region 8. The resultant folds are continuously discharged
from the folding apparatus by a mechanism. The gripping devices 4,
5 alternately release the contact with the material after the
completion of the folding process and return on the circumferential
guide path to the start of the folding process. The folds are
therefore created without influencing the speed {right arrow over
(V)}.sub.F of the separator material which is pulled in.
[0054] The features disclosed in the above description, the claims,
and the drawing may be of significance both individually and in any
combination for the implementation of the different
embodiments.
* * * * *